As the fifth anniversary of the 9/11 attacks approaches, President Bush is reemphasizing his focus on the war on terror as the defining struggle of the age. With historical analogies his constant tool, the president compares Osama bin Laden to the ideological foes the United States faced in the 20th century - Lenin and Hitler, for example - and likens the struggle against Islamic radicalism to the cold war.

Such comparisons can help Americans understand the foe the US is up against, analysts agree, and can help put the challenge ahead into perspective. For example, the cold war was an ideological battle spanning more than four decades, and the fight against terrorism is not likely to reach a decisive denouement anytime soon, experts say.

But such analogies go only so far and can actually hinder understanding if they obscure the differences in the current situation or act to cover up missteps in current policy.

"The cold war is a good template to begin to think about how to deal with the challenge of radical Islam," says Andrew Bacevich, a former Army colonel and now professor of international relations at Boston University. "The problem is that whatever the president is saying now, his administration's policies have not mirrored the policies of the cold war - starting with the fact that US strategy in the cold war was not primarily oriented towards an aggressive use of force."

Mr. Bush himself has said that the war on terror is not just a military battle, but the wars in Afghanistan and Iraq are nevertheless seen as the signature acts of the president's war on terror.

At the same time, Bush continues to draw comparisons between this war and 20th-century conflicts. "Bin Laden and his terrorist allies have made their intentions as clear as Lenin and Hitler before them," he said in Washington Tuesday in a speech to the Military Officers Association of America.

Such references are both useful and problematic, some experts say. "It's helpful to have things to point to that people can understand. But it's also true that historical analogies are rarely 100 percent accurate, and that can lead to misunderstandings," says Thomas Henriksen, a historian focusing on US foreign policy at the Hoover Institution in Stanford, Calif. "It's true that this will be a long conflict, and when the president says this is more than a military conflict, that's also true."...